How to get data in android from serial port
I am creating an android application for serial communication. Here I used an FTDI cable for serial communication between Android device and PC. To display data on my computer, I am using hyperterminal. I have created a successful connection between Android and my computer using FTDI and I have been sending data from the Android device to my computer successfully at a baud rate of 19200. But here I want to receive data that was sent by the PC to android using a serial cable which is bi-directional communication. Anyone can tell me how to do this. i did some code but it doesn't work please help me ...
This is my usb driver
package com.example.democomm;
import java.util.HashMap;
import java.util.Iterator;
import android.app.Activity;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.usb.UsbConstants;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import android.util.Log;
public class UsbDriver
{
private final Context mApplicationContext;
private final UsbManager mUsbManager;
@SuppressWarnings("unused")
private final UsbConnectionHandler mConnectionHandler;
private final int VID;
private final int PID;
protected static final String ACTION_USB_PERMISSION = "ch.serverbox.android.USB";
public static int Device_Exception;
public static UsbDevice Device_Details;
public static UsbEndpoint Data_In_End_Point = null;
public static UsbEndpoint Data_Out_End_Point = null;
public static UsbDeviceConnection USB_Device_Connection;
public UsbDriver(Activity parentActivity,UsbConnectionHandler connectionHandler, int vid, int pid)
{
mApplicationContext = parentActivity.getApplicationContext();
mConnectionHandler = connectionHandler;
mUsbManager = (UsbManager) mApplicationContext.getSystemService(Context.USB_SERVICE);
VID = 6790;
PID = 29987;
Device_Exception = 0;
// init();
Check_Devices();
}
private void Check_Devices()
{
@SuppressWarnings("unused")
int j=0;
HashMap<String, UsbDevice> devlist = mUsbManager.getDeviceList();
Iterator<UsbDevice> deviter = devlist.values().iterator();
Device_Details = null;
if (devlist.size() != 0)
{
while (deviter.hasNext())
{
Device_Details = deviter.next();
if (Device_Details.getVendorId() == VID && Device_Details.getProductId() == PID)
{
if (!mUsbManager.hasPermission(Device_Details))
{
onPermissionDenied(Device_Details);
}
else
{
UsbDeviceConnection conn = mUsbManager.openDevice(Device_Details);
if (!conn.claimInterface(Device_Details.getInterface(0), true))
{
return;
}
conn.controlTransfer(0x40, 0, 0, 0, null, 0, 0);// reset
conn.controlTransfer(0x40, 0, 1, 0, null, 0, 0);// clear Rx
conn.controlTransfer(0x40, 0, 2, 0, null, 0, 0);// clear Tx
conn.controlTransfer(0x40, 0x03, 0x809C, 0, null, 0, 0);
USB_Device_Connection=conn;
Data_In_End_Point = null;
Data_Out_End_Point = null;
UsbInterface usbIf = Device_Details.getInterface(0);
for (int i = 0; i < usbIf.getEndpointCount(); i++)
{
if (usbIf.getEndpoint(i).getType() == UsbConstants.USB_ENDPOINT_XFER_BULK)
{
if (usbIf.getEndpoint(i).getDirection() == UsbConstants.USB_DIR_IN)
Data_In_End_Point = usbIf.getEndpoint(i);
else
Data_Out_End_Point = usbIf.getEndpoint(i);
}
}
if (Data_In_End_Point == null || Data_Out_End_Point == null)
Device_Exception = 2;
}
break;
}j++;
}
if (Device_Details == null)
{
Device_Exception = 3;
return;
}
}
else
{
Device_Exception = 1;
return;
}
}
public void onPermissionDenied(UsbDevice d)
{
UsbManager usbman = (UsbManager) mApplicationContext.getSystemService(Context.USB_SERVICE);
PendingIntent pi = PendingIntent.getBroadcast(mApplicationContext, 0, new Intent(ACTION_USB_PERMISSION), 0);
mApplicationContext.registerReceiver(mPermissionReceiver,new IntentFilter(ACTION_USB_PERMISSION));
usbman.requestPermission(d, pi);
}
private class PermissionReceiver extends BroadcastReceiver
{
private final IPermissionListener mPermissionListener;
public PermissionReceiver(IPermissionListener permissionListener)
{
mPermissionListener = permissionListener;
}
@Override
public void onReceive(Context context, Intent intent)
{
mApplicationContext.unregisterReceiver(this);
if (intent.getAction().equals(ACTION_USB_PERMISSION))
{
if (!intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false))
{
mPermissionListener.onPermissionDenied((UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE));
}
else
{
l("Permission granted");
UsbDevice dev = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if (dev != null)
{
if (dev.getVendorId() == VID && dev.getProductId() == PID)
{
Check_Devices() ;
}
}
else
{
e("device not present!");
}
}
}
}
}
// MAIN LOOP
// END MAIN LOOP
private BroadcastReceiver mPermissionReceiver = new PermissionReceiver(new IPermissionListener()
{
@Override
public void onPermissionDenied(UsbDevice d)
{
l("Permission denied on " + d.getDeviceId());
}
});
private static interface IPermissionListener
{
void onPermissionDenied(UsbDevice d);
}
public final static String TAG = "USBController";
private void l(Object msg)
{
Log.d(TAG, ">==<" + msg.toString() + " >==<");
}
private void e(Object msg)
{
Log.e(TAG, ">==< " + msg.toString() + " >==<");
}
}
This is my main activity
package com.example.democomm;
import java.nio.ByteBuffer;
import java.util.HashMap;
import android.app.ActionBar;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Typeface;
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbEndpoint;
import android.hardware.usb.UsbInterface;
import android.hardware.usb.UsbManager;
import android.hardware.usb.UsbRequest;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity
{
public static final int targetVendorID = 6790;
public static final int targetProductID = 29987;
public UsbManager manager;
public UsbDeviceConnection usbDeviceConnection;
public UsbInterface usbInterfaceFound = null;
public UsbEndpoint endpointOut = null;
public UsbEndpoint endpointIn = null;
public UsbDevice usbdevice,device_details;
public UsbEndpoint listusbendpoint;
public static final String PREFS_NAME = "LoginPrefs";
HashMap<String, UsbDevice> devicelist= null;
int selectedendpoint;
static int Coil_No;
private static final int VID = 6790;
private static final int PID = 29987;
private static UsbDriver Usb_Driver_class;
ActionBar actionbar;
UsbConnectionHandler connectionHandler;
public static UsbDriver USB_Driver_Child;
public static boolean Communication_Failed,Frame_Ok,Total_Frame_Decoded;
static byte[] Communication_Byte;
public SharedPreferences loginpreferences;
public SharedPreferences.Editor loginpreferenceseditor;
public boolean savelogin;
public String Password;
Button sample_button;
public EditText receive_Data;
CheckBox remember_me;
Typeface custom_font;
String i = "";
Intent i2;
CheckBox show_password;
String ProcID;
String User_Name_string,password_string;
TextView title,username_txt,password_txt,company_name;
ByteBuffer buffer;
Button signin;
EditText dialog_username,dialog_password,dialog_confirm;
static byte[] sample;
static boolean Communication_Ok;
public static float []Wave_Form_Data=new float[1500];
public static float []Wave_Form_Data_1=new float[1500];
public static float Respsonse_Time,Drive_Voltage;
static int Sequence_No,Response_Time;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
receive_Data = (EditText)findViewById(R.id.edit_receive);
signin = (Button)findViewById(R.id.button1);
signin.setOnClickListener(new View.OnClickListener()
{
@SuppressWarnings("static-access")
@Override
public void onClick(View v)
{
Communication_Byte=new byte[1];
if(Check_Devices_Available()==true)
{
int Packet_Size = USB_Driver_Child.Data_In_End_Point.getMaxPacketSize();
Toast.makeText(MainActivity.this,""+Packet_Size, Toast.LENGTH_LONG).show();
Receive.start();
Communication_Ok=false;
for(int i=0;(i<5 && Communication_Ok!=true);i++)
Send_Communication_Check_Command();
if(Communication_Ok)
Toast.makeText(MainActivity.this, "Communication Successfully Established", 1000).show();
else
Toast.makeText(MainActivity.this, "Communication Failure", 10000).show();
}
}
});
}
public boolean Check_Devices_Available()
{
Usb_Driver_class = new UsbDriver(this, connectionHandler, VID, PID);
if(USB_Driver_Child.Device_Exception==0)
{
if(USB_Driver_Child.USB_Device_Connection==null || USB_Driver_Child.Data_Out_End_Point==null)
return false;
Toast.makeText(MainActivity.this,"Device Found", 1000).show();
return true;
}
else if(USB_Driver_Child.Device_Exception==1)
{
Toast.makeText(MainActivity.this,"No Devices Attached ", Toast.LENGTH_LONG).show();
return false;
}
else if(USB_Driver_Child.Device_Exception==2)
{
Toast.makeText(MainActivity.this,"Device Found,But No End Points", Toast.LENGTH_LONG).show();
return false;
}
else if(USB_Driver_Child.Device_Exception==3)
{
Toast.makeText(MainActivity.this,"Unable to Open Device", Toast.LENGTH_LONG).show();
return false;
}
return false; //un known exception
}
Thread Receive = new Thread(new Runnable()
{
@SuppressWarnings("unused")
@Override
public void run()
{
//Sequence_No=0;
buffer = ByteBuffer.allocate(64);
sample = new byte[64];
UsbRequest request = new UsbRequest();
int i,j;
byte [] datarx=new byte[1];
char q;
while (true)
{
request.initialize(USB_Driver_Child.USB_Device_Connection, USB_Driver_Child.Data_In_End_Point);
request.queue(buffer, 64);
if (USB_Driver_Child.USB_Device_Connection.requestWait() == request)
{
//UsbDriver.USB_Device_Connection.bulkTransfer(UsbDriver.Data_In_End_Point,datarx, datarx.length, 0);
sample=buffer.array();
for(i=0;i<64;i++)
{
receive_Data.setText(sample.toString());
if(sample[i]=='&')
{
Communication_Ok=true;
break;
}
}
}
}
}
});
private static void Send_Communication_Check_Command()
{
long i,j;
Communication_Byte[0]='&';
UsbDriver.USB_Device_Connection.bulkTransfer(UsbDriver.Data_Out_End_Point,Communication_Byte, 1, 0);
for(i=0;(i<1000 && Communication_Ok!=true) ;i++)
for(j=0;(j<1000 && Communication_Ok!=true);j++);
}
}
Here Inside a stream I wrote some code to receive data which didn't work
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1 answer
Amazing. I am posting an answer to my question. After doing a lot of searching, I found the answer in this one I used to display the received data in an edit textbox Here's what I did in my receive stream:
ByteBuffer buffer = ByteBuffer.allocate(1);
UsbRequest mUsbrequest = new UsbRequest();
mUsbrequest.initialize(Usb_Driver_class.USB_Device_Connection, Usb_Driver_class.Data_In_End_Point);
while(true){
mUsbrequest.queue(buffer, 1);
if(Usb_Driver_class.USB_Device_Connection.requestWait()==mUsbrequest){
byte dataReceive = buffer.get(0);
Log.d("Message", "Data to receive:"+dataReceive);
if(dataReceive!=0x00){//if data is null
string_to_receive+=(char)dataReceive;
runOnUiThread(new Runnable() {
@Override
public void run() {
receive_Data.setText(string_to_receive);
}
});
}
}
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